Periodic channel state information reporting for time division duplex (TDD) carrier aggregation systems

ABSTRACT

Technology for periodic channel state information (CSI) reporting is disclosed. One method can include a user equipment (UE) identifying a configured CSI reporting instance for a secondary cell to report the periodic CSI to a node based on a CSI reporting configuration of the secondary cell. The UE can determine that the configured CSI reporting instance of the secondary cell used to report the periodic CSI does not correspond with an uplink (UL) subframe of a primary cell. The UE can transmit the periodic CSI report for the secondary cell, to the node, using a physical uplink shared channel (PUSCH) on the secondary cell when the periodic CSI reporting instance for the secondary cell does not correspond with the UL subframe of the primary cell and an UL-SCH (Uplink Shared Channel) is available in a subframe that corresponds to the periodic CSI reporting instance of the secondary cell.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 61/707,784, filed Sep. 28, 2012, the entirespecification of which is hereby incorporated by reference in itsentirely for all purposes.

BACKGROUND

Wireless mobile communication technology uses various standards andprotocols to transmit data between a node (e.g., a transmission station)and a wireless device (e.g., a mobile device). Some wireless devicescommunicate using orthogonal frequency-division multiple access (OFDMA)in a downlink (DL) transmission and single carrier frequency divisionmultiple access (SC-FDMA) in an uplink (UL) transmission. Standards andprotocols that use orthogonal frequency-division multiplexing (OFDM) forsignal transmission include the third generation partnership project(3GPP) long term evolution (LTE), the Institute of Electrical andElectronics Engineers (IEEE) 802.16 standard (e.g., 802.16e, 802.16m),which is commonly known to industry groups as WiMAX (Worldwideinteroperability for Microwave Access), and the IEEE 802.11 standard,which is commonly known to industry groups as WiFi.

In 3GPP radio access network (RAN) LTE systems, the node can be acombination of Evolved Universal Terrestrial Radio Access Network(E-UTRAN) Node Bs (also commonly denoted as evolved Node Bs, enhancedNode Bs, eNodeBs, or eNBs) and Radio Network Controllers (RNCs), whichcommunicates with the wireless device, known as a user equipment (UE).The downlink (DL) transmission can be a communication from the node(e.g., eNodeB) to the wireless device (e.g., UE), and the uplink (UL)transmission can be a communication from the wireless device to thenode.

In homogeneous networks, the node, also called a macro node, can providebasic wireless coverage to wireless devices in a cell. The cell can bethe area in which the wireless devices are operable to communicate withthe macro node. Heterogeneous networks (HetNets) can be used to handlethe increased traffic loads on the macro nodes due to increased usageand functionality of wireless devices. HetNets can include a layer ofplanned high power macro nodes (or macro-eNBs) overlaid with layers oflower power nodes (small-eNBs, micro-eNBs, pico-eNBs, femto-eNBs, orhome eNBs [HeNBs]) that can be deployed in a less well planned or evenentirely uncoordinated manner within the coverage area (cell) of a macronode. The lower power nodes (LPNs) can generally be referred to as “lowpower nodes”, small nodes, or small cells.

The macro node can be used for basic coverage. The low power nodes canbe used to fill coverage holes, to improve capacity in hot-zones or atthe boundaries between the macro nodes' coverage areas, and improveindoor coverage where building structures impede signal transmission.Inter-cell interference coordination (ICIC) or enhanced ICIC (eICIC) maybe used for resource coordination to reduce interference between thenodes, such as macro nodes and low power nodes in a HetNet.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the disclosure will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the disclosure; and, wherein:

FIG. 1 illustrates a block diagram of various component carrier (CC)bandwidths in accordance with an example;

FIG. 2A illustrates a block diagram of multiple contiguous componentcarriers in accordance with an example;

FIG. 2B illustrates a block diagram of intra-band non-contiguouscomponent carriers in accordance with an example;

FIG. 2C illustrates a block diagram of inter-band non-contiguouscomponent carriers in accordance with an example;

FIG. 3A illustrates a block diagram of a symmetric-asymmetric carrieraggregation configuration in accordance with an example;

FIG. 3B illustrates a block diagram of an asymmetric-symmetric carrieraggregation configuration in accordance with an example;

FIG. 4 illustrates a block diagram of uplink radio frame resources(e.g., a resource grid) in accordance with an example;

FIG. 5 illustrates a block diagram of frequency hopping for a physicaluplink control channel (PUCCH) in accordance with an example;

FIG. 6 illustrates a table of physical uplink control channel (PUCCH)reporting types per PUCCH reporting mode and mode state in accordancewith an example;

FIG. 7 is a table for determining a periodicity value (N_(pd)) and anoffset value (N_(OFFSET/CQI)) according to a CQI-PMI configuration indexparameter (I_(CQI/PMI)) in accordance with an example;

FIG. 8 illustrates periodic channel state information (CSI) reportingsubframes for a primary cell and a secondary cell with different TimeDivision Duplex (TDD) uplink-downlink (UL-DL) configurations inaccordance with an example;

FIG. 9 depicts functionality of computer circuitry of a user equipment(UE) operable to report periodic channel state information (CSI) inaccordance with an example;

FIG. 10 depicts a flow chart of a method for periodic channel stateinformation (CSI) reporting at a wireless device in accordance with anexample;

FIG. 11 illustrates a block diagram of a serving node, a coordinationnode, and wireless device in accordance with an example; and

FIG. 12 illustrates a diagram of a wireless device (e.g., UE) inaccordance with an example.

Reference will now be made to the exemplary embodiments illustrated, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION

Before the present invention is disclosed and described, it is to beunderstood that this invention is not limited to the particularstructures, process steps, or materials disclosed herein, but isextended to equivalents thereof as would be recognized by thoseordinarily skilled in the relevant arts. It should also be understoodthat terminology employed herein is used for the purpose of describingparticular examples only and is not intended to be limiting. The samereference numerals in different drawings represent the same element.Numbers provided in flow charts and processes are provided for clarityin illustrating steps and operations and do not necessarily indicate aparticular order or sequence.

EXAMPLE EMBODIMENTS

An initial overview of technology embodiments is provided below and thenspecific technology embodiments are described in further detail later.This initial summary is intended to aid readers in understanding thetechnology more quickly but is not intended to identify key features oressential features of the technology nor is it intended to limit thescope of the claimed subject matter.

An increase in the amount of wireless data transmission has createdcongestion in wireless networks using licensed spectrum to providewireless communication services for wireless devices, such as smartphones and tablet devices. The congestion is especially apparent in highdensity and high use locations such as urban locations and universities.

One technique for providing additional bandwidth capacity to wirelessdevices is through the use carrier aggregation of multiple smallerbandwidths to form a virtual wideband channel at a wireless device(e.g., UE). In carrier aggregation (CA) multiple component carriers (CC)can be aggregated and jointly used for transmission to/from a singleterminal. Carriers can be signals in permitted frequency domains ontowhich information is placed. The amount of information that can beplaced on a carrier can be determined by the aggregated carrier'sbandwidth in the frequency domain. The permitted frequency domains areoften limited in bandwidth. The bandwidth limitations can become moresevere when a large number of users are simultaneously using thebandwidth in the permitted frequency domains.

FIG. 1 illustrates a carrier bandwidth, signal bandwidth, or a componentcarrier (CC) that can be used by the wireless device. For example, theLTE CC bandwidths can include: 1.4 MHz 210, 3 MHz 212, 5 MHz 214, 10 MHz216, 15 MHz 218, and 20 MHz 220. The 1.4 MHz CC can include 6 resourceblocks (RBs) comprising 72 subcarriers. The 3 MHz CC can include 15 RBscomprising 180 subcarriers. The 5 MHz CC can include 25 RBs comprising300 subcarriers. The 10 MHz CC can include 50 RBs comprising 600subcarriers. The 15 MHz CC can include 75 RBs comprising 900subcarriers. The 20 MHz CC can include 100 RBs comprising 1200subcarriers.

Carrier aggregation (CA) enables multiple carrier signals to besimultaneously communicated between a user's wireless device and a node.Multiple different carriers can be used. In some instances, the carriersmay be from different permitted frequency domains. Carrier aggregationprovides a broader choice to the wireless devices, enabling morebandwidth to be obtained. The greater bandwidth can be used tocommunicate bandwidth intensive operations, such as streaming video orcommunicating large data files.

FIG. 2A illustrates an example of carrier aggregation of continuouscarriers. In the example, three carriers are contiguously located alonga frequency band. Each carrier can be referred to as a componentcarrier. In a continuous type of system, the component carriers arelocated adjacent one another and can be typically located within asingle frequency band (e.g., band A). A frequency band can be a selectedfrequency range in the electromagnetic spectrum. Selected frequencybands are designated for use with wireless communications such aswireless telephony. Certain frequency bands are owned or leased by awireless service provider. Each adjacent component carrier may have thesame bandwidth, or different bandwidths. A bandwidth is a selectedportion of the frequency band. Wireless telephony has traditionally beenconducted within a single frequency band. In contiguous carrieraggregation, only one fast Fourier transform (FFT) module and/or oneradio frontend may be used. The contiguous component carriers can havesimilar propagation characteristics which can utilize similar reportsand/or processing modules.

FIGS. 2B-2C illustrates an example of carrier aggregation ofnon-continuous component carriers. The non-continuous component carriersmay be separated along the frequency range. Each component carrier mayeven be located in different frequency bands. Non-contiguous carrieraggregation can provide aggregation of a fragmented spectrum. Intra-band(or single-band) non-contiguous carrier aggregation providesnon-contiguous carrier aggregation within a same frequency band (e.g.,band A), as illustrated in FIG. 2B. Inter-band (or multi-band)non-contiguous carrier aggregation provides non-contiguous carrieraggregation within different frequency bands (e.g., bands A, B, or C),as illustrated in FIG. 2C. The ability to use component carriers indifferent frequency bands can enable more efficient use of availablebandwidth and increases the aggregated data throughput.

Network symmetric (or asymmetric) carrier aggregation can be defined bya number of downlink (DL) and uplink (UL) component carriers offered bya network in a sector. UE symmetric (or asymmetric) carrier aggregationcan be defined by a number of downlink (DL) and uplink (UL) componentcarriers configured for a UE. The number of DL CCs may be at least thenumber of UL CCs. A system information block type 2 (SIB2) can providespecific linking between the DL and the UL by means of signaling EUTRAAbsolute Radio Frequency Channel Number (EARFCN) for the UL which isassociated with a corresponding DL. FIG. 3A illustrates a block diagramof a symmetric-asymmetric carrier aggregation configuration, where thecarrier aggregation is symmetric between the DL and UL for the networkand asymmetric between the DL and UL for the UE. FIG. 3B illustrates ablock diagram of an asymmetric-symmetric carrier aggregationconfiguration, where the carrier aggregation is asymmetric between theDL and UL for the network and symmetric between the DL and UL for theUE.

A component carrier can be used to carry channel information via a radioframe structure transmitted on the physical (PHY) layer in a uplinktransmission between a node (e.g., eNodeB) and the wireless device(e.g., UE) using a generic long term evolution (LTE) frame structure, asillustrated in FIG. 4. While an LTE frame structure is illustrated, aframe structure for an IEEE 802.16 standard (WiMax), an IEEE 802.11standard (WiFi), or another type of communication standard using SC-FDMAor OFDMA may also be used.

FIG. 4 illustrates an uplink radio frame structure. In the example, aradio frame 100 of a signal used to transmit control information or datacan be configured to have a duration, T_(f), of 10 milliseconds (ms).Each radio frame can be segmented or divided into ten subframes 110 ithat are each 1 ms long. Each subframe can be further subdivided intotwo slots 120 a and 120 b, each with a duration, T_(slot), of 0.5 ms.Each slot for a component carrier (CC) used by the wireless device andthe node can include multiple resource blocks (RBs) 130 a, 130 b, 130 i,130 m, and 130 n based on the CC frequency bandwidth. Each RB (physicalRB or PRB) 130 i can include 12-15 kHz subcarriers 136 (on the frequencyaxis) and 6 or 7 SC-FDMA symbols 132 (on the time axis) per subcarrier.The RB can use seven SC-FDMA symbols if a short or normal cyclic prefixis employed. The RB can use six SC-FDMA symbols if an extended cyclicprefix is used. The resource block can be mapped to 84 resource elements(REs) 140 i using short or normal cyclic prefixing, or the resourceblock can be mapped to 72 REs (not shown) using extended cyclicprefixing. The RE can be a unit of one SC-FDMA symbol 142 by onesubcarrier (i.e., 15 kHz) 146. Each RE can transmit two bits 150 a and150 b of information in the case of quadrature phase-shift keying (QPSK)modulation. Other types of modulation may be used, such as 16 quadratureamplitude modulation (QAM) or 64 QAM to transmit a greater number ofbits in each RE, or bi-phase shift keying (BPSK) modulation to transmita lesser number of bits (a single bit) in each RE. The RB can beconfigured for an uplink transmission from the wireless device to thenode.

Reference signals (RS) can be transmitted by SC-FDMA symbols viaresource elements in the resource blocks. Reference signals (or pilotsignals or tones) can be a known signal used for various reasons, suchas to synchronize timing, estimate a channel, and/or noise in thechannel. Reference signals can be received and transmitted by wirelessdevices and nodes. Different types of reference signals (RS) can be usedin a RB. For example, in LTE systems, uplink reference signal types caninclude a sounding reference signal (SRS) and a UE-specific referencesignal (UE-specific RS or UE-RS) or a demodulation reference signal(DM-RS). In LTE systems, downlink reference signal types can includechannel state information reference signals (CSI-RS) which can bemeasured by a wireless device to provide CSI reports on a channel.

An uplink signal or channel can include data on a Physical Uplink SharedCHannel (PUSCH) or control information on a Physical Uplink ControlCHannel (PUCCH). In LTE, the uplink physical channel (PUCCH) carryinguplink control information (UCI) can include channel state information(CSI) reports, Hybrid Automatic Retransmission reQuest (HARQ)ACKnowledgment/Negative ACKnowledgment (ACK/NACK) and uplink schedulingrequests (SR).

The wireless device can provide aperiodic CSI reporting using the PUSCHor periodic CSI reporting using PUCCH. The PUCCH can support multipleformats (i.e., PUCCH format) with various modulation and coding schemes(MCS), as shown for LTE in Table 1. For example, PUCCH format 3 can beused to convey multi-bit HARQ-ACK, which can be used for a UE supportingcarrier aggregation in Time Division Duplex (TDD).

TABLE 1 PUCCH Modulation Number of bits per format scheme subframe,M_(bit) 1 N/A N/A 1a BPSK 1 1b QPSK 2 2 QPSK 20 2a QPSK + BPSK 21 2bQPSK + QPSK 22 3 QPSK 48

In another example, PUCCH format 2 can use frequency hopping, asillustrated in FIG. 5. Frequency hopping can be a method of transmittingradio signals by rapidly switching a carrier among many frequencychannels using a pseudorandom sequence or specified sequence known toboth a transmitter (e.g., UE in an uplink) and a receiver (e.g., eNB inthe uplink). Frequency hopping can enable the UE to exploit thefrequency diversity of a wideband channel used in LTE in an uplink whilekeeping a contiguous allocation (in the time domain).

The PUCCH can include various channel state information (CSI) reports.The CSI components in the CSI reports can include a channel qualityindicator (CQI), a precoding matrix indicator (PMI), a precoding typeindicator (PTI), and/or rank indication (RI) reporting type. The CQI canbe signaled by a UE to the eNodeB to indicate a suitable data rate, suchas a modulation and coding scheme (MCS) value, for downlinktransmissions, which can be based on a measurement of the receiveddownlink signal to interference plus noise ratio (SINR) and knowledge ofthe UE's receiver characteristics. The PMI can be a signal fed back bythe UE to support multiple-input multiple-output (MIMO) operation. ThePMI can correspond to an index of the precoder (within a codebook sharedby the UE and eNodeB), which can maximize an aggregate number of databits which can be received across all downlink spatial transmissionlayers. PTI can be used to distinguish slow from fast fadingenvironments. The RI can be signaled to the eNodeB by UEs configured forPDSCH transmission modes 3 (e.g., open-loop spatial multiplexing) and 4(e.g., closed-loop spatial multiplexing). RI can correspond to a numberof useful transmission layers for spatial multiplexing (based on theUE's estimate of the downlink channel), enabling the eNodeB to adapt thePDSCH transmissions accordingly.

The granularity of a CQI report can be divided into three levels:wideband, UE selected subband, and higher layer configured subband. Thewideband CQI report can provide one CQI value for an entire downlinksystem bandwidth. The UE selected subband CQI report can divide thesystem bandwidth into multiple subbands, where the UE can select a setof preferred subbands (the best M subbands), then report one CQI valuefor the wideband and one differential CQI value for the set (assumingtransmission only over the selected M subbands). The higher layerconfigured subband CQI report can provide a highest granularity. In thehigher layer configured subband CQI report, the wireless device candivide the entire system bandwidth into multiple subbands, then reportsone wideband CQI value and multiple differential CQI values, such as onefor each subband.

The UCI carried by the PUCCH can use different PUCCH reporting types (orCQI/PMI and RI reporting types) to specify which CSI reports are beingtransmitted. For example, PUCCH reporting Type 1 can support CQIfeedback for UE selected sub-bands; Type 1a can support subband CQI andsecond PMI feedback; Type 2, Type 2b, and Type 2c can support widebandCQI and PMI feedback; Type 2a can support wideband PMI feedback; Type 3can supports RI feedback; Type 4 can supports wideband CQI; Type 5 cansupport RI and wideband PMI feedback; and Type 6 can support RI and PTIfeedback.

Different CSI components can be included based on the PUCCH reportingtype. For example, RI can be included in PUCCH reporting types 3, 5, or6. Wideband PTI can be included in PUCCH reporting type 6. Wideband PMIcan be included in PUCCH reporting types 2a or 5. Wideband CQI can beincluded in PUCCH reporting types 2, 2b, 2c, or 4. Subband CQI can beincluded in PUCCH reporting types 1 or 1a.

The CQI/PMI and RI (PUCCH) reporting types with distinct periods andoffsets can be supported for the PUCCH CSI reporting modes illustratedby the table in FIG. 5. FIG. 5 illustrates an example for LTE of thePUCCH reporting type and payload size per PUCCH reporting mode and modestate.

The CSI information reported can vary based on the downlink transmissionscenarios used. The various scenarios for the downlink can be reflectedin different transmission modes (TMs). For example, in LTE, TM 1 can usea single transmit antenna; TM 2 can use transmit diversity; TM 3 can useopen loop spatial multiplexing with cyclic delay diversity (CDD); TM 4can use closed loop spatial multiplexing; TM 5 can use multi-user MIMO(MU-MIMO); TM 6 can use closed loop spatial multiplexing using a singletransmission layer; TM 7 can use beamforming with UE-specific RS; TM 8can use single or dual-layer beamforming with UE-specific RS; and TM 9can use a multilayer transmission to support closed-loop single userMIMO (SU-MIMO) or carrier aggregation. In an example, TM 10 can be usedfor coordinated multipoint (CoMP) signaling, such as joint processing(JP), dynamic point selection (DPS), and/or coordinatedscheduling/coordinated beamforming (CS/CB).

Each transmission mode can use different PUCCH CSI reporting modes,where each PUCCH CSI reporting mode can represent different CQI and PMIfeedback types, as shown for LTE in Table 2.

TABLE 2 PMI Feedback Type Single No PMI PMI PUCCH CQI Wideband Mode 1-0Mode 1-1 Feedback Type (wideband CQI) UE Selected Mode 2-0 Mode 2-1(subband CQI)

For example, in LTE, TMs 1, 2, 3, and 7 can use PUCCH CSI reportingmodes 1-0 or 2-0; TMs 4, 5, and 6 can use PUCCH CSI reporting modes 1-1or 2-1; TM 8 can use PUCCH CSI reporting modes 1-1 or 2-1 if the UE isconfigured with PMI/RI reporting, or PUCCH CSI reporting modes 1-0 or2-0 if the UE is configured without PMI/RI reporting; and TMs 9 and 10can use PUCCH CSI reporting modes 1-1 or 2-1 if the UE is configuredwith PMI/RI reporting and number of CSI-RS ports is greater than one, orPUCCH CSI reporting modes 1-0 or 2-0 if the UE is configured withoutPMI/RI reporting or number of CSI-RS ports is equal to one. Based on thedownlink transmission scheme (e.g., transmission mode), a UE cangenerate more CSI reports than may be permitted to be transmitted tonodes (e.g., eNBs) without generating a signal collision orinterference. The wireless device (e.g. UE) may make a determination onthe CSI reports to keep and transmit and which CSI reports to drop ordiscard (and not transmit) to avoid a collision on a subframe.

In CSI reporting, the PUCCH format 2 can convey 4 to 11 CSI(CQI/PMI/PTI/RI) bits from the UE to the eNB. In carrier aggregation,each serving cell can be independently configured by radio resourcecontrol (RRC) signaling regarding a CSI configuration, such as aperiodicity, a starting offset, or a PUCCH mode. However, thetransmission of CSI using PUCCH format 2 may only be performed inprimary cell. In an example using PUCCH format 2, one CSI report for aspecified serving cell may be transmitted while the remaining CSIreports for other serving cells may be dropped when more than one CSIreport for multiple serving cells has a potential to collide with eachother in a same subframe. Dropping the CSI reports for other servingcells may prevent the collision of the CSI reports in the same subframe.In an example, the criteria used to determine the priority of a periodicCSI reports transmitted and the periodic CSI reports that are droppedcan be based on a PUCCH reporting type with a lower CSI reporting typepriority being dropped. PUCCH reporting types 3, 5, 6, and 2a can have ahighest or top priority, and PUCCH reporting types 2, 2b, 2c, and 4 canhave a next priority or a second priority, and PUCCH reporting types 1and 1a can have a third or lowest priority. So, the UE can drop the CSIreports with PUCCH reporting types 1, 1a, first, then drop the CSIreports with PUCCH reporting types 2, 2b, 2c, and 4, second, then dropany CSI reports with PUCCH reporting types 3, 5, 6, and 2a above thenumber of CSI report(s) to be transmitted. In an example, a CSI reportcan be generated for each component carrier (CC). Each CC can berepresented by a serving cell index (i.e., ServCellIndex). Among CSIreports having reporting types with a same priority (e.g., PUCCHreporting types 3, 5, 6, and 2a), a priority of a cell can decrease asthe corresponding serving cell index (i.e., ServCellIndex) increases(i.e., the lower cell index has higher priority).

In another example, the CSI report priority can be based on the CSIcomponent, where RI and wideband PMI reporting have a higher prioritythan CQI reporting, and wideband CQI reporting has a higher prioritythan subband CQI reporting. RI can have a higher priority because RI canprovide general information about a network channel condition. In anexample, PMI and CQI can be dependent on RI. Wideband CQI can havehigher priority than subband CQI, because wideband CQI can providegeneral quality information about a channel or to a worst case scenarioof the channel, whereas the subband CQI provides narrower subbandchannel quality information.

FIG. 7 is a table for determining a reporting periodicity value (N_(pd))and a subframe offset value (N_(OFFSET,CQI)) according to a CQI-PMIconfiguration index parameter (I_(CQI/PMI)) in Frequency Division Duplex(FDD), half-duplex FDD, and Time Division Duplex (TDD). For each servingcell, the N_(pd) (in subframes) and the N_(OFFSET,CQI) (in subframes)for periodic CQI/PMI reporting may be determined based on theI_(CQI/PMI) configuration index parameter. The UE may receive theI_(CQI/PMI) configuration index parameter from an evolved node B (eNB)and calculate the corresponding reporting periodicity N_(pd) and thesubframe offset value N_(OFFSET,CQI). In one example, the I_(CQI/PMI)configuration index parameter may be configured by Radio ResourceControl (RRC) signaling.

In periodic CQI/PMI reporting for TDD, the periodicity values (e.g., 1,5, 10, etc.) may depend on the TDD UL/DL configuration for a servingcell. For example, the reporting period of N_(pd)=1 for a serving cellmay be applicable to TDD UL/DL configurations 0, 1, 3, 4, and 6 for theserving cell, where all UL subframes in a radio frame are used forCQI/PMI reporting. The reporting period of N_(pd)=5 for a serving cellmay be applicable to TDD UL/DL configurations 0, 1, 2, and 6 for theserving cell. In addition, the reporting periods of N_(pd)={10, 20, 40,80, 160} may be applicable to all TDD UL/DL configurations (i.e., TDDUL/DL configurations 0, 1, 2, 3, 4, 5, and 6).

FIG. 8 illustrates periodic channel state information (CSI) reportingsubframes for a primary cell and a secondary cell with different TimeDivision Duplex (TDD) uplink-downlink (UL-DL) configurations. The UE mayperiodically measure the CSI of each of the radio channels used fortransmitting data to the UE and report the CSI to the eNB via an uplinkfeedback channel. The uplink feedback channel may be included in aPhysical Uplink Control Channel (PUCCH) or a Physical Uplink SharedChannel (PUSCH). The content of the CSI may include a rank indicator(RI), a channel quality indicator (CQI), a precoding type indicator(PTI), and/or a precoding matrix indicator (PMI) for each downlinkcomponent carrier (CC). In carrier aggregation, the downlink CC mayinclude a primary cell and/or up to four secondary cells. For each ofthe downlink CCs that are being used to transmit data to the UE, the UEmay periodically report the CSI to the eNB via the uplink feedbackchannel.

The periodic CSI report for each serving cell (i.e., the primary celland up to four secondary cells) may be independently configured forcarrier aggregation. Thus, each serving cell may be configured to reportCSI to the eNB based on a periodicity value or a reporting period (i.e.,N_(pd)) and an offset value (i.e., N_(OFFSET,CQI)). The periodicityvalue and the offset value may be used to determine one or more periodicCSI reporting instances for the serving cell. In other words, theperiodic CSI reporting instances for the serving cell may correspondwith uplink (UL) subframes of the serving cell. Thus, the UL subframesof the serving cell may be used to periodically report the CSI to theeNB based on the periodicity and offset of the serving cell.

In carrier aggregation, the periodic CSI report for the secondary cellmay be transmitted to the eNB by a Physical Uplink Control Channel(PUCCH) on the primary cell. In particular, the periodic CSI report ofthe secondary cell may be transmitted via the PUCCH on the primary cellwhen the periodic CSI reporting instance of the secondary cellcorresponds with an UL subframe of the primary cell. In other words, thesecondary cell may be scheduled to report the periodic CSI at an ULsubframe that corresponds with the UL subframe in the primary cell. Inparticular, the periodic CSI report of the secondary cell may betransmitted via PUCCH format 2, 2a, 2b, or 3 on the primary cell.

In one configuration, the primary cell may have a Time Division Duplex(TDD) Uplink-Downlink (UL-DL) configuration different than the TDD UL-DLconfiguration of the secondary cell. For example, the primary cell mayhave a TDD UL-DL configuration of 2 and the secondary cell may have aTDD UL-DL configuration of 1. Since the periodic CSI report of theprimary cell may be transmitted to the eNB on the PUCCH on the primarycell, the different TDD UL-DL configurations of the primary cell and thesecondary cell may not affect the periodic CSI report of the primarycell. However, due to the different TDD UL-DL configurations, theperiodic CSI report for the secondary cell may be scheduled during aperiodic CSI reporting instance that does not correspond with the ULsubframe in the primary cell. As a result, the UE may be unable toreport the periodic CSI for the secondary cell to the eNB. In otherwords, if the primary cell and the secondary cell have different TDDUL-DL configurations, then the UL-DL patterns between the primary celland the secondary cell may not match and periodic CSI reports for thesecondary cell may not be transmitted via the primary cell.

As shown in FIG. 8, the primary cell may have TDD UL-DL configuration 2and the secondary cell may have TDD UL-DL configuration 1. TheI_(CQI/PMI) value of the primary cell may be 3 (i.e., the N_(pd)=5 andthe N_(OFFSET,CQI)=2) and the I_(CQI/PMI) value of the secondary cellmay be 4 (i.e., the N_(pd)=5 and the N_(OFFSET,CQI)=3). Therefore, theUE does not have an UL subframe in the primary cell to transmit theperiodic CSI report for the secondary cell. In contrast, if the primarycell and the secondary cell have the same TDD UL-DL configuration, theprimary cell may have an UL subframe to send the periodic CSI report forthe secondary cell to the eNB when the secondary cell has an ULsubframe.

In order to report the CSI of the secondary cell based on a periodic CSIreporting instance when the primary cell does not have a correspondingUL subframe, the UE may perform one or more actions. For example, the UEmay determine that the secondary cell has a Physical Uplink SharedChannel (PUSCH) on the periodic CSI reporting instance (i.e., the ULsubframe) of the secondary cell. In other words, the UE may determinethat, on the UL subframe of the secondary cell that is scheduled toreport the CSI, the secondary cell has a PUSCH. Thus, the UE maymultiplex the periodic CSI report for the secondary cell on the PUSCHwhen the UL subframe is unavailable on the primary cell and an UL-SCH(Uplink Shared Channel) on the secondary cell is available in the ULsubframe of the secondary cell. Therefore, the UE may transmit uplinkcontrol information (UCI), such as the periodic CSI report for thesecondary cell, and the UL-SCH using the PUSCH of the secondary cell.

In one configuration, the UE may drop the periodic CSI report for thesecondary cell in response to determining that the periodic CSIreporting instance for the secondary cell does not correspond with theUL subframe of the primary cell. In addition, the UE may drop theperiodic CSI report when the secondary cell does not include the PUSCHwith the UL-SCH. In other words, the UE may drop the periodic CSI reportfor the secondary cell that was scheduled to be transmitted to the eNBby PUCCH format 2 or 2a or 2b or 3 on the primary cell.

Since the UE may transmit the periodic CSI report for the secondary cellin the PUCCH of the primary cell, the following periodicity values mayapply depending on the TDD UL/DL configuration: the reporting period ofNpd=1 for a serving cell may apply to TDD UL-DL configurations 0, 1, 3,4, or 6 for the primary cell and all UL subframes of the primary cellare used for periodic CSI reporting, the Npd value of 5 for a servingcell may apply to TDD UL-DL configurations 0, 1, 2, or 6 for the primarycell, and the Npd value of 10, 20, 40, 80, or 160 for a serving cell mayapply to TDD UL-DL configurations 0, 1, 2, 3, 4, 5, or 6 for the primarycell. In other words, the above periodicity values may identify which ULsubframes are available for the primary cell based on the N_(pd) valuefor a serving cell, as PUCCH is transmitted on the primary cell and notthe secondary cell.

In addition, the periodic reporting time definitions may be modified inreference to the primary cell which transmits the periodic CSI of thesecondary cell, to the eNB, on the PUCCH on the primary cell. Theperiodic reporting time may be given below. In the case where widebandCQI/PMI reporting is configured, the reporting instances for widebandCQI/PMI are subframes satisfying(10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI))mod(N_(pd))=0, where n_(f) is thesystem frame number and n_(s) is the slot index within a subframe (0to 1) for the primary cell. In addition, N_(OFFSET,CQI) is thecorresponding wideband CQI/PMI reporting offset in subframes, and N_(pd)is the wideband CQI/PMI period in subframes. The parametersN_(OFFSET,CQI) and N_(pd) are for the primary cell or the secondary cellconfigured by RRC signaling.

In case RI reporting is configured, the reporting interval of the RIreporting is an integer multiple M_(RI) of period Npd (in subframes).The parameter M_(RI) is selected from the set {1, 2, 4, 8, 16, 32, OFF}.The reporting instances for RI are subframes satisfying(10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI)−N_(OFFSET,RI))mod(N_(pd)·M_(RI))=0,where N_(OFFSET,RI) is the corresponding relative RI offset to thewideband CQI/PMI reporting offset in subframes. In addition,N_(OFFSET,RI) may be a parameter for the primary cell or the secondarycell configured by RRC signaling.

The periodicity N_(pd) and the offset N_(OFFSET,CQI) for widebandCQI/PMI reporting are determined based on the parametercqi-pmi-ConfigurationIndex. The periodicity M_(RI) and offsetN_(OFFSET,RI) for RI reporting are determined based on the parameterri-ConfigurationIndex. Both cqi-pmi-ConfigurationIndex andri-ConfigurationIndex are configured by higher-layer signaling from theeNB to the UE.

In the case where both wideband CQI/PMI and subband CQI reporting areconfigured, the reporting instances for wideband CQI are subframessatisfying (10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI))mod N_(pd)=0.

The PTI may not be transmitted (e.g., the PTI may not be configured) orthe most recently transmitted PTI may be equal to 1. As a result, thewideband CQI/wideband PMI (or wideband CQI/wideband second PMI fortransmission mode 9) report has period (H·N_(pd), and is reported on thesubframes satisfying (10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI))mod(H·N_(pd))=0.The integer H is defined as H=J·K+1, where J is the number of bandwidthparts. As previously stated, n_(f) is the system frame number and n_(s)is the slot index within a subframe (0 to 1) for the primary cell. Inaddition, the parameters N_(OFFSET,CQI), H, J, K and N_(pd) are for theprimary cell and the secondary cell configured by RRC signaling.

Between every two consecutive wideband CQI/wideband PMI (or widebandCQI/wideband second PMI for transmission mode 9) reports, the remainingJ·K reporting instances are used in sequence for subband CQI reports onK full cycles of bandwidth parts except when the gap between twoconsecutive wideband CQI/PMI reports contains less than J·K reportinginstances due to a system frame number transition to 0, in which casethe UE shall not transmit the remainder of the subband CQI reports whichhave not been transmitted before the second of the two widebandCQI/wideband PMI (or wideband CQI/wideband second PMI for transmissionmode 9) reports. Each full cycle of bandwidth parts shall be inincreasing order starting from bandwidth part 0 to bandwidth part J-1.The parameter K is configured by higher-layer signaling.

When the most recently transmitted PTI is 0, the wideband firstprecoding matrix indicator report has period H′·N_(pd), and is reportedon the subframes satisfying(10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI))mod(H′·N_(pd))=0, where H′ issignaled by higher layers. In addition, H′ may be for the primary cellor the secondary cell configured by RRC signaling. Between every twoconsecutive wideband first precoding matrix indicator reports, theremaining reporting instances are used for a wideband second precodingmatrix indicator with wideband CQI as described below.

In case RI reporting is configured, the reporting interval of RI isM_(RI) times the wideband CQI/PMI period H·N_(pd), and RI is reported onthe same PUCCH cyclic shift resource as both the wideband CQI/PMI andsubband CQI reports. The reporting instances for RI are subframessatisfying(10×n_(f)+└n_(s)/2┘−N_(OFFSET,CQI)−N_(OFFSET,RI))mod(H·N_(pd)·M_(RI))=0.As previously discussed, n_(f) and n_(s) are, respectively, the systemframe number and slot index within a subframe (0 to 1) for the primarycell. In addition, the parameters N_(OFFSET,CQI) N_(OFFSET,RI), H,N_(pd), J, K, etc. may be for the primary cell or the secondary cellconfigured by RRC signaling. As a result, the periodic reporting timesinclude that the primary cell may transmit the periodic CSI report forthe secondary cell via the PUCCH on the primary cell.

In one configuration, the network (e.g., the eNB) may verify that theperiodic CSI reporting configuration (e.g., periodicity, offset) for theCQI/PMI/RI/PTI reporting for the secondary cell is the same as theperiodic CSI reporting configuration of the primary cell. For example,the UE may receive, from the eNB, a CSI reporting configuration of thesecondary cell, based on a Channel Quality Index-Precoding MatrixIndicator (CQI-PMI) configuration index that determines both aperiodicity (N_(pd)) and an offset for the periodic CSI reportinginstance in the UL subframes. In addition, the UE may receive the CSIreporting configuration of the secondary cell that corresponds with aCSI reporting configuration of the primary cell. The network may verifythat the CSI reporting configuration of the secondary cell is the sameas the CSI reporting configuration of the primary cell, which mayminimize the likelihood of the periodic CSI report of the secondary cellbeing dropped because there is no corresponding UL subframe in theprimary cell.

In addition, the UE may override the CSI reporting configuration (e.g.,the periodicity and offset) of the secondary cell with the CSI reportingconfiguration of the primary cell when the UL subframe on the secondarycell does not correspond with the UL subframe on the primary cell. Inother words, the CSI reporting configuration of the primary cell may beapplied to the secondary cell. As a result, the DL/UL subframes betweenthe primary cell and the secondary cell may match, thereby providing anUL subframe on the primary cell during the periodic CSI reportinginstance of the secondary cell.

In one configuration, the network (e.g., the eNB) may verify that theperiodic CSI report for the secondary cell is not scheduled to occurduring an UL subframe of the secondary cell when the primary cell doesnot have an UL subframe. In addition, the UE may receive a ChannelQuality Index-Precoding Matrix Indicator (CQI-PMI) configuration indexfor the primary cell to enable the periodic CSI reporting instance forthe secondary cell to correspond with the UL subframe of the primarycell. As a result, the UE may transmit the periodic CSI report for thesecondary cell on the PUCCH on the primary cell without dropping theperiodic CSI report of the secondary cell.

In order to perform the PUCCH transmission on the primary cell for theperiodic CSI report of the secondary cell, the network (e.g., the eNB)may configure the periodicity of the periodic CSI reports to at least 10ms. For example the periodicity of the periodic CSI reports may be every10, 20, 40, 80, or 160 milliseconds (ms).

In one configuration, the UE may delay the periodic CSI report for thesecondary cell to a succeeding UL subframe of the primary cell when theUL subframe on the primary cell does not correspond to the periodic CSIreporting instance on the secondary cell. For example, the UE may delaythe periodic CSI report to the next available UL subframe in the primarycell. The UE may determine that the periodic CSI report delayed to thesucceeding UL subframe in the primary cell collides with a previouslyscheduled periodic CSI report to occur during the succeeding UL subframe(i.e., two CSI reports are attempting to be transmitted in the samesubframe). Thus, the UE may drop the periodic CSI report with a lowerCSI reporting type priority between the colliding CSI reports. Forexample, the PUCCH reporting types 3, 5, 6, and 2a may have a priorityhigher than PUCCH reporting types 1, 1a, 2, 2b, 2c, and 4, and PUCCHreporting types 2, 2b, 2c, and 4 may have a priority higher than PUCCHreporting types 1 and 1a. In one example, a priority of a cell decreasesas the corresponding serving cell index (i.e., ServCellIndex) increaseswhen the CSI reporting types are the same priority level. In otherwords, the lower cell index has a lower priority level.

In a scenario when carrier aggregation and coordinated multipoint (CoMP)transmission mode 10 are applied together, a report type has a priorityhigher than the CSI process index and the serving cell index, and theCSI process index has a priority higher than the serving cell index. Fora UE in transmission mode 10, a collision between the periodic CSIreports of the same serving cell with the PUCCH reporting type of thesame priority, and the CSI reports correspond to different CSIprocesses, the periodic CSI reports corresponding to all CSI processesexcept the CSI process with the lowest CSIProcessIndex may be dropped.For a given subframe and UE in transmission mode 10, the periodic CSIreports of all serving cells except the serving cell with a lowestserving cell index (i.e., ServCellIndex) may be dropped when theperiodic CSI reports of different serving cells with PUCCH reportingtypes of the same priority collides with the periodic CSI reportscorresponding to CSI processes with a same CSIProcessIndex. For a givensubframe and UE in transmission mode 10, the periodic CSI reports of allserving cells except the serving cell with periodic CSI reportscorresponding to a CSI process with the lowest CSIProcessIndex may bedropped when the periodic CSI reports of different serving cells with aPUCCH reporting type of the same priority level collides with theperiodic CSI reports corresponding to CSI processes with a differentCSIProcessIndex. Therefore, periodic CSI reports that collide with otherCSI reports (i.e., in the same UL subframe of the primary cell) may bedropped according to the above dropping principles.

In one configuration, the network (e.g., the eNB) may verify that thep-CSI configuration for the secondary cell is a subset of the p-CSIconfiguration of the primary cell. However, the offset value may or maynot be the same. For example, the p-CSI configuration I_(CQI/PMI) forthe primary cell may be 1 (i.e., N_(pd)=5 and N_(OFFSET,CQI)=0).Therefore, the eNB may ensure that the p-CSI configuration I_(CQI/PMI)for the secondary cell is 7 (i.e., N_(pd)=10 and N_(OFFSET,CQI)=1). As aresult, the PUCCH transmission may occur on the primary cell for theperiodic CSI report of the secondary cell.

Another example provides functionality 900 of computer circuitry of auser equipment (UE) operable to report periodic channel stateinformation (CSI), as shown in the flow chart in FIG. 9. Thefunctionality may be implemented as a method or the functionality may beexecuted as instructions on a machine, where the instructions areincluded on at least one computer readable medium or one non-transitorymachine readable storage medium. The computer circuitry can beconfigured to identify a reporting period and an offset period for asecondary cell to report the periodic CSI to an evolved node B (eNB)based on a CSI reporting configuration of the secondary cell, as inblock 910. The computer circuitry can be further configured to determinethat an uplink (UL) subframe of a primary cell used to report theperiodic CSI using a Physical Uplink Control Channel (PUCCH) on theprimary cell corresponds to a periodic CSI reporting instance of thesecondary cell, the reporting instance being determined based on thereporting period and the offset period for the secondary cell, as inblock 920. The computer circuitry can also be configured to transmit theperiodic CSI report for the secondary cell, to the eNB, using the PUCCHon the primary cell, as in block 930.

In one configuration, the computer circuitry can be configured todetermine that the subframe corresponding to the to a periodic CSIreporting instance of the secondary cell does not correspond with the ULsubframe of the primary cell; and transmit the periodic CSI report forthe secondary cell, to the eNB, using a Physical Uplink Shared Channel(PUSCH) on the secondary cell. In addition, the computer circuitry maybe configured to transmit the periodic CSI report for the secondary cellusing the PUCCH on the primary cell, wherein a reporting period ofN_(pd)=1 for a serving cell applies to Time-Division Duplex (TDD)uplink-downlink (UL-DL) configurations 0, 1, 3, 4, or 6 for the primarycell and all UL subframes of the primary cell are used for periodic CSIreporting, the N_(pd) value of 5 applies to TDD UL-DL configurations 0,1, 2, or 6 for the primary cell, and the N_(pd) value of 10, 20, 40, 80,or 160 applies to TDD UL-DL configurations 0, 1, 2, 3, 4, 5, or 6 forthe primary cell.

In an example, the UL subframe of the primary cell can be used totransmit the periodic CSI of the secondary cell to the eNB when theperiodic CSI reporting instance for the secondary cell corresponds withthe UL subframe of the primary cell. In addition, the primary cell canhave a Time-Division Duplex (TDD) uplink-downlink (UL-DL) configurationdifferent than the TDD UL-DL configuration of the secondary cell.

In another example, the computer circuitry can be configured to drop theperiodic CSI report for the secondary cell in response to determiningthat the periodic CSI reporting instance for the secondary cell does notcorrespond with the UL subframe of the primary cell. Furthermore, theperiodic CSI report for the secondary cell can be transmitted on one ofa Physical Uplink Control Channel (PUCCH) format 2 or 2a or 2b or 3 ofthe primary cell when the UL subframe of the primary cell correspondswith the periodic CSI reporting instance for the secondary cell.

In one configuration, the computer circuitry can be configured tomultiplex the periodic CSI report for the secondary cell on a PhysicalUplink Shared Channel (PUSCH) of the secondary cell when the UL subframeis unavailable on the primary cell and an UL-SCH (Uplink Shared Channel)on the secondary cell is available in the UL subframe of the secondarycell. In addition, the computer circuitry can be configured to receivethe CSI reporting configuration of the secondary cell, based on aChannel Quality Index-Precoding Matrix Indicator (CQI-PMI) configurationindex that determines both the reporting period (Npd) and the offsetperiod for the periodic CSI reporting instance in the UL subframes ofthe secondary cell.

In addition, the computer circuitry may be configured to override theCSI reporting configuration of the secondary cell with a CSI reportingconfiguration of the primary cell when the periodic CSI reportinginstance for the secondary cell does not correspond with the UL subframeon the primary cell.

Another example provides a method 1000 for periodic channel stateinformation (CSI) reporting, as shown in the flow chart in FIG. 10. Themethod may be executed as instructions on a machine, where theinstructions are included on at least one computer readable medium orone non-transitory machine readable storage medium. The method includesthe operation of identifying, at a user equipment (UE), a periodic CSIreporting instance for a secondary cell to report the periodic CSI to anode based on a CSI reporting configuration of the secondary cell, as inblock 1010. The method can include determining that the periodic CSIreporting instance of the secondary cell used to report the periodic CSIdoes not correspond with an uplink (UL) subframe of a primary cell, asin block 1020. The next operation of the method can be determining thatthe periodic CSI reporting instance on the secondary cell used to reportthe periodic CSI includes a physical uplink shared channel (PUSCH), asin block 1030. The method can further include transmitting the periodicCSI report for the secondary cell, to the node, using the PUSCH on thesecondary cell when the periodic CSI reporting instance for thesecondary cell does not correspond with the UL subframe of the primarycell and an UL-SCH (Uplink Shared Channel) is available in a subframethat corresponds to the periodic CSI reporting instance of the secondarycell, as in block 1040.

In one configuration, the method can include multiplexing the periodicCSI report of the secondary cell on the PUSCH of the secondary cell; andtransmitting uplink control information (UCI) and the uplink sharedchannel (UL-SCH) using the PUSCH of the secondary cell. In addition, themethod can include dropping the periodic CSI report for the secondarycell when the periodic CSI reporting instance for the secondary does notcorrespond with the UL subframe on the primary cell and the secondarycell does not include the PUSCH with the UL-SCH. In one example, theprimary cell has a Time-Division Duplex (TDD) uplink-downlink (UL-DL)configuration different than the TDD UL-DL configuration of thesecondary cell.

In one configuration, the method can include receiving a Channel QualityIndex-Precoding Matrix Indicator (CQI-PMI) configuration index for theprimary cell to enable the periodic CSI reporting instance for thesecondary cell to correspond with the UL subframe of the primary cell.In addition, the method may include selecting a Channel QualityIndex-Precoding Matrix Indicator (CQI-PMI) configuration index toprovide a periodicity (Npd) of greater than 10 milliseconds (ms) for thesecondary cell. Furthermore, the method can include delaying theperiodic CSI for the secondary cell to a succeeding UL subframe of theprimary cell when the UL subframe on the primary cell does notcorrespond to the periodic CSI reporting instance on the secondary cell.

In one example, the method can further include determining that theperiodic CSI report delayed to the succeeding UL subframe in the primarycell collides with a scheduled periodic CSI report to be performed onthe succeeding UL subframe in the primary cell; and dropping theperiodic CSI report based on a priority level of the periodic CSIreport, wherein PUCCH reporting types 3, 5, 6, and 2a have a priorityhigher than PUCCH reporting types 1, 1a, 2, 2b, 2c, and 4, and PUCCHreporting types 2, 2b, 2c, and 4 have a priority higher than PUCCHreporting types 1 and 1a.

In another configuration, the method can include determining that thep-CSI configuration of the secondary cell is a subset of the p-CSIconfiguration of the primary cell. In one example, the node can beselected from the group consisting of a base station (BS), a Node B(NB), an evolved Node B (eNB), a baseband unit (BBU), a remote radiohead (RRH), a remote radio equipment (RRE), a remote radio unit (RRU),and combinations thereof.

FIG. 11 illustrates an example node (e.g., serving node 1110 andcooperation node 1130) and an example wireless device 1120. The node caninclude a node device 1112 and 1132. The node device or the node can beconfigured to communicate with the wireless device. The node device canbe configured to receive periodic channel state information (CSI). Thenode device or the node can be configured to communicate with othernodes via a backhaul link 1140 (optical or wired link), such as an X2application protocol (X2AP). The node device can include a processingmodule 1114 and 1134 and a transceiver module 1116 and 1136. Thetransceiver module can be configured to receive a periodic channel stateinformation (CSI) in a PUCCH. The transceiver module 1116 and 1136 canbe further configured to communicate with the coordination node via anX2 application protocol (X2AP). The processing module can be furtherconfigured to process the periodic CSI reports of the PUCCH. The node(e.g., serving node 1110 and cooperation node 1130) can include a basestation (BS), a Node B (NB), an evolved Node B (eNB), a baseband unit(BBU), a remote radio head (RRH), a remote radio equipment (RRE), or aremote radio unit (RRU).

The wireless device 1120 can include a transceiver module 1124 and aprocessing module 1122. The wireless device can be configured for aperiodic channel state information (CSI) reporting. The processingmodule can be configured to identify a periodic CSI reporting instancefor a secondary cell to report the periodic CSI to an evolved node B(eNB), based on a CSI reporting configuration of the secondary cell;determine that the periodic CSI reporting instance for the secondarycell used to report the periodic CSI does not correspond with an ULsubframe of a primary cell; and determine that the periodic CSIreporting instance for the secondary cell used to report the periodicCSI includes a physical uplink shared channel (PUSCH). The transceivermodule can be configured to transmit the periodic CSI report for thesecondary cell, to the eNB, using the PUSCH on the secondary cell.

In one example, the processing module can be further configured tomultiplex the periodic CSI report of the secondary cell on the PUSCH ofthe secondary cell before uplink control information (UCI) and an uplinkshared channel (UL-SCH) are transmitted to the eNB using the PUSCH ofthe secondary cell. In addition, the processing module can be configuredto receive a CSI reporting configuration of the secondary cell thatcorresponds with a CSI reporting configuration of the primary cell,based on a Channel Quality Index-Precoding Matrix Indicator (CQI-PMI)configuration index that determines both a reporting period (N_(pd)) andan offset period for the CSI reporting in UL subframes of the secondarycell.

In another example, an Npd value of 1 applies to Time-Division Duplex(TDD) uplink-downlink (UL-DL) configurations 0, 1, 3, 4, and 6 for theprimary cell and all UL subframes of the primary cell are used forperiodic CSI reporting, the Npd value of 5 applies to TDD UL-DLconfigurations 0, 1, 2, and 6 for the primary cell, and the Npd value of10, 20, 40, 80, or 160 applies to TDD UL-DL configurations 0, 1, 2, 3,4, 5, and 6.

FIG. 12 provides an example illustration of the wireless device, such asuser equipment (UE), a mobile station (MS), a mobile wireless device, amobile communication device, a tablet, a handset, or other type ofwireless device. The wireless device can include one or more antennasconfigured to communicate with a node, macro node, low power node (LPN),or, transmission station, such as a base station (BS), an evolved Node B(eNB), a baseband unit (BBU), a remote radio head (RRH), a remote radioequipment (RRE), a relay station (RS), a radio equipment (RE), or othertype of wireless wide area network (WWAN) access point. The wirelessdevice can be configured to communicate using at least one wirelesscommunication standard including 3GPP LTE, WiMAX, High Speed PacketAccess (HSPA), Bluetooth, and WiFi. The wireless device can communicateusing separate antennas for each wireless communication standard orshared antennas for multiple wireless communication standards. Thewireless device can communicate in a wireless local area network (WLAN),a wireless personal area network (WPAN), and/or a WWAN.

FIG. 12 also provides an illustration of a microphone and one or morespeakers that can be used for audio input and output from the wirelessdevice. The display screen may be a liquid crystal display (LCD) screen,or other type of display screen such as an organic light emitting diode(OLED) display. The display screen can be configured as a touch screen.The touch screen may use capacitive, resistive, or another type of touchscreen technology. An application processor and a graphics processor canbe coupled to internal memory to provide processing and displaycapabilities. A non-volatile memory port can also be used to providedata input/output options to a user. The non-volatile memory port mayalso be used to expand the memory capabilities of the wireless device. Akeyboard may be integrated with the wireless device or wirelesslyconnected to the wireless device to provide additional user input. Avirtual keyboard may also be provided using the touch screen.

Various techniques, or certain aspects or portions thereof, may take theform of program code (i.e., instructions) embodied in tangible media,such as floppy diskettes, CD-ROMs, hard drives, non-transitory computerreadable storage medium, or any other machine-readable storage mediumwherein, when the program code is loaded into and executed by a machine,such as a computer, the machine becomes an apparatus for practicing thevarious techniques. Circuitry can include hardware, firmware, programcode, executable code, computer instructions, and/or software. Anon-transitory computer readable storage medium can be a computerreadable storage medium that does not include signal. In the case ofprogram code execution on programmable computers, the computing devicemay include a processor, a storage medium readable by the processor(including volatile and non-volatile memory and/or storage elements), atleast one input device, and at least one output device. The volatile andnon-volatile memory and/or storage elements may be a RAM, EPROM, flashdrive, optical drive, magnetic hard drive, solid state drive, or othermedium for storing electronic data. The node and wireless device mayalso include a transceiver module, a counter module, a processingmodule, and/or a clock module or timer module. One or more programs thatmay implement or utilize the various techniques described herein may usean application programming interface (API), reusable controls, and thelike. Such programs may be implemented in a high level procedural orobject oriented programming language to communicate with a computersystem. However, the program(s) may be implemented in assembly ormachine language, if desired. In any case, the language may be acompiled or interpreted language, and combined with hardwareimplementations.

It should be understood that many of the functional units described inthis specification have been labeled as modules, in order to moreparticularly emphasize their implementation independence. For example, amodule may be implemented as a hardware circuit comprising custom VLSIcircuits or gate arrays, off-the-shelf semiconductors such as logicchips, transistors, or other discrete components. A module may also beimplemented in programmable hardware devices such as field programmablegate arrays, programmable array logic, programmable logic devices or thelike.

Modules may also be implemented in software for execution by varioustypes of processors. An identified module of executable code may, forinstance, comprise one or more physical or logical blocks of computerinstructions, which may, for instance, be organized as an object,procedure, or function. Nevertheless, the executables of an identifiedmodule need not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposefor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.The modules may be passive or active, including agents operable toperform desired functions.

Reference throughout this specification to “an example” means that aparticular feature, structure, or characteristic described in connectionwith the example is included in at least one embodiment of the presentinvention. Thus, appearances of the phrases “in an example” in variousplaces throughout this specification are not necessarily all referringto the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various embodiments and example of the presentinvention may be referred to herein along with alternatives for thevarious components thereof. It is understood that such embodiments,examples, and alternatives are not to be construed as defactoequivalents of one another, but are to be considered as separate andautonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of layouts, distances, network examples, etc., to provide athorough understanding of embodiments of the invention. One skilled inthe relevant art will recognize, however, that the invention can bepracticed without one or more of the specific details, or with othermethods, components, layouts, etc. In other instances, well-knownstructures, materials, or operations are not shown or described indetail to avoid obscuring aspects of the invention.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

What is claimed is:
 1. A user equipment (UE), the UE comprisingcircuitry configured to: identify a reporting period and an offsetperiod for a secondary cell to report a periodic channel stateinformation (CSI) report for the secondary cell to an evolved node B(eNB) based on a CSI reporting configuration of the secondary cell;identify if an uplink (UL) subframe of a primary cell used to send aperiodic CSI report using a Physical Uplink Control Channel (PUCCH) onthe primary cell corresponds to a subframe of a periodic CSI reportinginstance of the secondary cell; identify if the UL subframe of theprimary cell does not correspond to the subframe of the periodic CSIreporting instance of the secondary cell, the periodic CSI reportinginstance being determined based on the reporting period and the offsetperiod for the secondary cell; transmit the periodic CSI report for thesecondary cell, to the eNB, using the PUCCH on the primary cell when theUL subframe of the primary cell corresponds to the subframe of theperiodic CSI reporting instance of the secondary cell; and drop theperiodic CSI report for the secondary cell when the subframe of theperiodic CSI reporting instance for the secondary cell does notcorrespond with the UL subframe of the primary cell.
 2. The UE of claim1, wherein the circuitry is further configured to transmit the periodicCSI report for the secondary cell using the PUCCH on the primary cell,wherein a reporting period of N_(pd)=1 for a serving cell applies toTime-Division Duplex (TDD) uplink-downlink (UL-DL) configurations 0, 1,3, 4, or 6 for the primary cell and all UL subframes of the primary cellare used for periodic CSI reporting, the N_(pd) value of 5 applies toTDD UL-DL configurations 0, 1, 2, or 6 for the primary cell, and theN_(pd) value of 10, 20, 40, 80, or 160 applies to TDD UL-DLconfigurations 0, 1, 2, 3, 4, 5, or 6 for the primary cell.
 3. The UE ofclaim 1, wherein the primary cell has a Time-Division Duplex (TDD)uplink-downlink (UL-DL) configuration different than a TDD UL-DLconfiguration of the secondary cell.
 4. The UE of claim 1, wherein theperiodic CSI report for the secondary cell is transmitted on one of aPUCCH format 2 or 2a or 2b or 3 of the primary cell when the UL subframeof the primary cell corresponds with the subframe of the periodic CSIreporting instance for the secondary cell.
 5. The UE of claim 1, whereinthe circuitry is further configured to multiplex the periodic CSI reportfor the secondary cell on a Physical Uplink Shared Channel (PUSCH) ofthe secondary cell when the UL subframe is unavailable on the primarycell and an UL-SCH (Uplink Shared Channel) on the secondary cell isavailable in an UL subframe of the secondary cell.
 6. The UE of claim 1,wherein the circuitry is further configured to receive the CSI reportingconfiguration of the secondary cell from the eNB, based on a ChannelQuality Index-Precoding Matrix Indicator (CQI-PMI) configuration indexthat determines both a reporting period (N_(pd)) and an offset periodfor the periodic CSI reporting instance for UL subframes of thesecondary cell.
 7. The UE of claim 1, wherein the circuitry is furtherconfigured to override the CSI reporting configuration of the secondarycell with a CSI reporting configuration of the primary cell when thesubframe of the periodic CSI reporting instance for the secondary celldoes not correspond with the UL subframe on the primary cell.